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1. Field of the Invention
The apparatus and method of the present invention relates to monitoring or measuring torque. More particularly, the apparatus and method of the present invention relates to a system for measuring the amount of torque between stationary and rotatable members, and more particular, through compression of members within the apparatus as torque is applied, for example, in measuring torque in a drill string, while undertaking various types of operations.
2. General Background of the Invention
In the drilling of oil wells, the drill string from time to time must be prevented from rotating so that either wireline work must be done, or additional sections of pipe added onto the string. Usually, it is important that the amount of torque on the drill string be known in order to conduct certain operations on the drill floor. In the present state of the art, the torque on a drill string is usually measured by tongs which are equipped with sensors or the like to measure the amount of torque on the string. This is quite common, and is important, for example when a section of drill pipe is being added to the string, so that one knows the precise amount of torque in order to insure the joint will not leak.
Recently there have been developed several systems which include swivels which can be locked and unlocked between an upper drive portion and the rig floor. For example, one system is disclosed in U.S. Pat. No. 5,996,712, entitled xe2x80x9cMechanical Locking Swivel Apparatus.xe2x80x9d This device allows for a manual coupling and uncoupling of the drill string from the upper drive system when one wishes to connect or disconnect. A second system is disclosed in U.S. Pat. No. 6,244,345 entitled xe2x80x9cLockable Swivel Apparatus and Methodxe2x80x9d which also allows for the coupling and uncoupling of the drill string from the upper drive system through the use of hydraulic fluid moving a mandrel within the apparatus when one wishes to connect or disconnect between the upper drive and the drill string. One problem which is derived with the use of either of these systems is that the systems both eliminate the use of tongs on the drill string when the string is uncoupled. That being the case, there is no precise way to measure the torque on the string when the locking swivel apparatus is in the locked position. Likewise, during a backoff job, there is a need to know the amount of torque which is being applied to the string in either direction so as to assure integrity of the job. Therefore, without the tong line, and because of the locking and unlocking swivels, there is a need for a method and a device to measure the torque when the locking and unlocking swivels are being used, since there are no tongs on the system.
The apparatus and system of the present invention solves the problems in the art in a simple and straightforward manner. What is provided is a torque swivel system which includes a torque swivel apparatus positioned in the drill string above the rotary table between an upper drive assembly and a locking and unlocking swivel of the type used in wireline or other types of drilling/recovery operations. The torque swivel includes an upper body assembly which would engage to a top drive assembly or to a wireline entry tool, and a lower body assembly which would engage into the upper portion of a locking and unlocking swivel secured in the drill string at the rotary table. The upper assembly would provide a pair of milled out wedge portions for accommodating a pair of wedge members in the lower body assembly to engage therein during coupling. There would further be provided a plurality of hydraulic cylinders positioned into the upper body assembly, with a piston member secured within each cylinder, and extending out into the milled out wedge portions, so that each of the four faces of the wedge portions of the upper body assembly accommodates a pair of pistols in its wall. The outer face of each of the pistons would make contact with each of the four faces of the wedge members of the lower body assembly, when coupling has occurred. The inner face of each of the pistons would mate with a hydraulic line having hydraulic fluid, which when acted upon would register force against the piston. Therefore, when there is torque applied to the drill string in a first direction, the face of the lower body assembly would press against two pistons in each of two faces of the upper body assembly, and the amount of force on the fluid would register on a gauge as ft./lbs. Of torque. Likewise, if the torque was applied in the opposite direction, the force would register against the other two faces of the upper body assembly, and the ft./lbs. Of force would register.
In the broadest sense what is disclosed is a method of measuring torque between a first stationary member and a second member comprising the steps of placing a torque swivel between the first and second members; applying rotational force to the second member, so that the amount of torque applied to the second member is measured by the torque swivel.
In practical application, the method involves using the torque swivel apparatus to measure torque in a drill string which is rotated by an upper drive unit for various drilling operations on an oil rig, by providing a torque swivel below the upper drive unit; locking and unlocking the drill string from the torque swivel; and then measuring the amount of torque placed on the drill string as sensed by the torque swivel while the drill sting is locked to the torque swivel.
When engaged in a method of measuring torque in a drill string during drilling operations, one would provide an upper drive unit; then provide a locking and unlocking swivel below the upper drive unit; position a torque swivel between the upper drive unit and a locking and unlocking swivel; lock the locking and unlocking swivel; and then rotate the drill string below the torque swivel; and measure the torque applied to the drill string as rotational force is applied to the drill string.
Another embodiment of the method would be measuring torque in a drill string during wireline operations, by providing an upper drive unit; placing a side or top entry device below the drive unit; providing a torque swivel below the entry device; positioning a locking and unlocking swivel between the torque swivel and the drill string below; locking the locking and unlocking swivel; applying rotational force to the drill string below the torque swivel; and measuring the torque applied to the drill string be rotated.
Another embodiment of the method of measuring torque would be in a drill string during pipeline recovery operations, by providing an upper drive unit; providing a torque swivel below the upper drive unit; positioning a locking and unlocking swivel between the torque swivel and the drill string below; locking the locking and unlocking swivel; rotating the drill string below the torque swivel to effect pipe line recovery; and measuring the torque applied to the drill string during the process.
A yet additional embodiment of the method of measuring torque in a drill string to perform wireline operations, wherein the drill string includes a wireline access device, is providing a torque measuring swivel below the wireline access device; providing a means for locking and unlocking the drill string below the torque measuring device from the torque measuring device; and measuring the torque on the drill string when the drill string is locked to the torque measuring device and rotational force is applied to the drill string.
Therefore, it is a principal object of the present invention to provide an apparatus, method and system for measuring torque in a drill string without the use of tongs and in combination with any locking swivel apparatus.
It is a further object of the present invention to provide an apparatus positionable in the drill string above the rig floor which measures torque by force applied to hydraulically operated piston members within the apparatus.
It is a further object of the present invention to allow torque on a drill string to be measured in either direction without the use of tongs.
It is a further object of the present invention to provide a method of measuring torque in a drill string above the rig floor when rotational force is applied to the drill string during all drilling/recovery operations, including wireline, pipe recovery, or other operations by measuring the torque applied to the string with a torque swivel apparatus.